Growth of the High-T_c Phase in the Bi-Pb-Sr-Ca-Cu-O Superconducting Oxide System

Abstract

We studied the effects of the sintering temperature and the cooling rate on the depth profiles of the fraction of the high- T c phase in the Bi-Pb-Sr-Ca-Cu-O superconductors. We used X-ray diffraction patterns to estimate the fraction of the high- T c phase. We found that the larger fraction of the high- T c phase grew inside the samples. Such depth profiles can possibly be explained by the desorption of oxygen in heating and the absorption of oxygen in cooling.